The invention relates to novel 1,4-diamino-2-alkenylbenzene derivatives and to agents containing these compounds and used for coloring keratin fibers.
In the area of keratin fiber dyeing, particularly hair dyeing, oxidation dyes have attained substantial importance. In this case, the coloration is produced by reaction of certain developers with certain couplers in the presence of an appropriate oxidant. Suitable developers are, in particular, 2,5-diaminotoluene, 2,5-diaminophenylethyl alcohol, p-aminophenol, 1,4-diaminobenzene and 4,5-diaminopyrazole, and suitable couplers are, for example, resorcinol, 4-chlororesorcinol, 1-naphthol, 3-aminophenol, m-phenylenediamine, 2-amino-4-(2′-hydroxyethyl)aminoanisole, 1,3-diamino-4-(2′-hydroxyethoxy)benzene and 2,4-diamino-5-fluorotoluene.
The oxidation dyes used for dyeing human hair must meet numerous requirements in addition to that of being able to produce colorations of the desired intensity. For example, these dyes must be harmless from a toxicological and dermatological standpoint, and the hair colorations obtained must have good light fastness, resistance to permanent waving, acid fastness and rubbing fastness. In any case, however, in the absence of exposure to light, rubbing and chemicals, such colorations must remain stable over a period of at least 4 to 6 weeks. Moreover, by combining appropriate developers and couplers, it must be possible to create a wide range of different color shades.
European Patent EP 0 819 424 and European Unexamined Patent Application EP 0 634 163 describe oxidation dyes containing as the developer a 2-alkyl-p-phenylenediamine or a salt thereof, among others.
A need, however, continued to exist for novel developers capable of meeting the requirements for oxidative dye percursors to a major extent.